BobV said:65shlbycln - I think your car is actually going to be 39, not 40. They weren't building fastbacks yet in May of 64.
Mine hits 40 on November 15 of this year, and it's "fairly" early for 65FB production.
I see you picked up on that too. I know there were not any 64-1/2 fastbacks so I have to assume it is May of '65 too. Mine was June 10th 1964.